106 



GEOLOGICAL SUEVEY OF THE TEERITOEIES. 



white crust, with a few scattered springs, mostly dead. The first 

 group does not diifer materially from those described on the East Fork. 

 The aggrega,ted waters form a little stream, which flows westward into 



a small lake in a 

 grove of pines; 

 thence southwest 

 into the Fire-Hole 

 Eiver. (Fig. 37.) 

 One of the springs 

 we named the 

 Thumping or Thud 

 Geyser, from the 

 dull, suppressed 

 sound which is given 

 off as thewaterrises 

 and recedes. The 

 orifice has a beauti- 

 fully scalloped rim, 

 with small basins 

 around it, 185°. 

 . There is also a long 

 i fissure -spring, the 

 • opening 40 feet long, 

 I 4 feet wide, and 10 

 I feet deep, clear as 

 1 crystal, 175°. Also 

 I a large basin nearly 

 i circular, 50 feet in 

 !. diameter, with a 

 I number of huge 

 : apertures, some of 

 which throw the wa- 

 ter up 30 feet. From 

 one orifice the water 

 shoots up continu- 

 ally 4 to 6 feet. All 

 around this geyser- 

 group are several 

 smaller springs con- 

 tinually bubbling. 

 There are also a 

 number of reser- 

 voirs once in an act- 

 ive state. There are 

 large numbers of 

 small geysers, some 

 constantly shooting 

 up 2 to 10 feet 5 oth- 

 ers in a violent state 

 of ebullition, rising 

 and falling ; the lat- 

 ter might l3e called 

 pulsating springs. 

 There is one beauti- 

 ful spring, with a basin so large that it looks like a small lake, 25 by 30 

 feet, and one can look from the margin down into its clear depths for over 





